// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/compositor/compositor_vsync_manager.h"

namespace ui {

CompositorVSyncManager::CompositorVSyncManager()
    : authoritative_vsync_interval_(base::TimeDelta::FromSeconds(0))
{
}

CompositorVSyncManager::~CompositorVSyncManager() { }

void CompositorVSyncManager::SetAuthoritativeVSyncInterval(
    base::TimeDelta interval)
{
    authoritative_vsync_interval_ = interval;
    last_interval_ = interval;
    NotifyObservers(last_timebase_, last_interval_);
}

void CompositorVSyncManager::UpdateVSyncParameters(base::TimeTicks timebase,
    base::TimeDelta interval)
{
    if (authoritative_vsync_interval_ != base::TimeDelta::FromSeconds(0))
        interval = authoritative_vsync_interval_;
    last_timebase_ = timebase;
    last_interval_ = interval;
    NotifyObservers(timebase, interval);
}

void CompositorVSyncManager::AddObserver(Observer* observer)
{
    observer_list_.AddObserver(observer);
    observer->OnUpdateVSyncParameters(last_timebase_, last_interval_);
}

void CompositorVSyncManager::RemoveObserver(Observer* observer)
{
    observer_list_.RemoveObserver(observer);
}

void CompositorVSyncManager::NotifyObservers(base::TimeTicks timebase,
    base::TimeDelta interval)
{
    FOR_EACH_OBSERVER(CompositorVSyncManager::Observer, observer_list_,
        OnUpdateVSyncParameters(timebase, interval));
}

} // namespace ui
